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Willis B. Person

Other affiliations: Polish Academy of Sciences
Bio: Willis B. Person is an academic researcher from University of Florida. The author has contributed to research in topics: Infrared spectroscopy & Infrared. The author has an hindex of 41, co-authored 165 publications receiving 6122 citations. Previous affiliations of Willis B. Person include Polish Academy of Sciences.


Papers
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Journal ArticleDOI
TL;DR: In this article, the SCF results in polarized basis sets are believed to be sufficiently accurate to suggest that the cis form of H2POH was that observed in the matrix rather than the trans form.

20 citations

Journal ArticleDOI
TL;DR: In this article, the structures and stabilization energies of guanine-cytosine and adenine-thymine base pairs were studied using a combined quantum-mechanical approach, an ab initio calculation for relative stabilities of the isolated tautomers together with a calculation of intermolecular interaction energies using a multipolar expansion method developed by Claverie and co-workers.

20 citations

Journal ArticleDOI
TL;DR: In this article, the intensities of four infrared-active fundamentals of C2F6 have been determined and interpreted in terms of the bond-moment hypothesis, and an internal check is provided.
Abstract: The intensities of four of the infrared‐active fundamentals of C2F6 have been determined and interpreted in terms of the bond‐moment hypothesis. The bond‐moment parameters are overdetermined so that an internal check is provided. This check, supplemented by comparison with data on related molecules, shows that the bond‐moment picture is a useful approximation but that it is not quantitatively reliable.

20 citations

Journal ArticleDOI
TL;DR: In this paper, the Dipolemoment derivatives, ∂p/∂Sj, have been calculated for the infrared active symmetry species of BF3, using approximate wavefunctions from the CNDO/2 procedure of Pople and Segal.
Abstract: Dipole‐moment derivatives, ∂p/∂Sj, have been calculated (according to the method of Segal and Klein) for the infrared‐active symmetry species of BF3, using approximate wavefunctions from the CNDO/2 procedure of Pople and Segal. The results agree fairly closely with the experimental values determined by McKean. In an attempt to understand the calculated ∂ p/∂ Sj values more fully, we have analyzed them in terms of derivatives (∂ μ/∂ rk) with respect to the generalized internal coordinates, rk. The latter calculated derivatives have been further analyzed in order to deduce the magnitudes of the different factors contributing to the values of ∂ μ/∂ rk. Comparison is made with corresponding values from the related F2CO molecule.

18 citations


Cited by
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Journal ArticleDOI
TL;DR: The mechanisms of tissue bonding to bioactive ceramics are beginning to be understood, which can result in the molecular design of bioceramics for interfacial bonding with hard and soft tissues.
Abstract: Ceramics used for the repair and reconstruction of diseased or damaged parts of the musculo-skeletal system, termed bioceramics, may be bioinert (alumina, zirconia), resorbable (tricalcium phosphate), bioactive (hydroxyapatite, bioactive glasses, and glass-ceramics), or porous for tissue ingrowth (hydroxyapatite-coated metals, alumina). Applications include replacements for hips, knees, teeth, tendons, and ligaments and repair for periodontal disease, maxillofacial reconstruction, augmentation and stabilization of the jaw bone, spinal fusion, and bone fillers after tumor surgery. Carbon coatings are thromboresistant and are used for prosthetic heart valves. The mechanisms of tissue bonding to bioactive ceramics are beginning to be understood, which can result in the molecular design of bioceramics for interfacial bonding with hard and soft tissues. Composites are being developed with high toughness and elastic modulus match with bone. Therapeutic treatment of cancer has been achieved by localized delivery of radioactive isotopes via glass beads. Development of standard test methods for prediction of long-term (20-year) mechanical reliability under load is still needed.

4,292 citations

Journal Article
TL;DR: The mechanisms of tissue bonding to bioactive ceramics are beginning to be understood, which can result in the molecular design of bioceramics for interfacial bonding with hard and soft tissues.
Abstract: Ceramics used for the repair and reconstruction of diseased or damaged parts of the musculo-skeletal system, termed bioceramics, may be bioinert (alumina, zirconia), resorbable (tricalcium phosphate), bioactive (hydroxyapatite, bioactive glasses, and glass-ceramics), or porous for tissue ingrowth (hydroxyapatite-coated metals, alumina). Applications include replacements for hips, knees, teeth, tendons, and ligaments and repair for periodontal disease, maxillofacial reconstruction, augmentation and stabilization of the jaw bone, spinal fusion, and bone fillers after tumor surgery. Carbon coatings are thromboresistant and are used for prosthetic heart valves. The mechanisms of tissue bonding to bioactive ceramics are beginning to be understood, which can result in the molecular design of bioceramics for interfacial bonding with hard and soft tissues. Composites are being developed with high toughness and elastic modulus match with bone. Therapeutic treatment of cancer has been achieved by localized delivery of radioactive isotopes via glass beads. Development of standard test methods for prediction of long-term (20-year) mechanical reliability under load is still needed.

4,213 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present conformational energies for a molecular mechanical model (Parm99) developed for organic and biological molecules using the restrained electrostatic potential (RESP) approach to derive the partial charges.
Abstract: In this study, we present conformational energies for a molecular mechanical model (Parm99) developed for organic and biological molecules using the restrained electrostatic potential (RESP) approach to derive the partial charges. This approach uses the simple "generic" force field model (Parm94), and attempts to add a minimal number of extra Fourier components to the torsional energies, but doing so only when there is a physical justification. The results are quite encouraging, not only for the 34-molecule set that has been studied by both the highest level ab initio model (GVB/LMP2) and experiment, but also for the 55-molecule set for which high-quality experimental data are available. Considering the 55 molecules studied by all the force field models for which there are experimental data, the average absolute errors (AAEs) are 0.28 (this model), 0.52 (MM3), 0.57 (CHARMm (MSI)), and 0.43 kcal/mol (MMFF). For the 34-molecule set, the AAEs of this model versus experiment and ab initio are 0.28 and 0.27 kcal/mol, respectively. This is a lower error than found with MM3 and CHARMm, and is comparable to that found with MMFF (0.31 and 0.22 kcal/mol). We also present two examples of how well the torsional parameters are transferred from the training set to the test set. The absolute errors of molecules in the test set are only slightly larger than in the training set (differences of <0.1 kcal/mol). Therefore, it can be concluded that a simple "generic" force field with a limited number of specific torsional parameters can describe intra- and intermolecular interactions, although all comparison molecules were selected from our 82-compound training set. We also show how this effective two-body

3,748 citations

Journal ArticleDOI
TL;DR: An all atom potential energy function for the simulation of proteins and nucleic acids and the first general vibrational analysis of all five nucleic acid bases with a molecular mechanics potential approach is presented.
Abstract: We present an all atom potential energy function for the simulation of proteins and nucleic acids. This work is an extension of the CH united atom function recently presented by S.J. Weiner et al. J. Amer. Chem. Soc., 106, 765 (1984). The parameters of our function are based on calculations on ethane, propane, n−butane, dimethyl ether, methyl ethyl ether, tetrahydrofuran, imidazole, indole, deoxyadenosine, base paired dinucleoside phosphates, adenine, guanine, uracil, cytosine, thymine, insulin, and myoglobin. We have also used these parameters to carry out the first general vibrational analysis of all five nucleic acid bases with a molecular mechanics potential approach.

3,291 citations

Journal ArticleDOI
TL;DR: The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.
Abstract: The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

2,582 citations